General Tools 89 Stainless Steel Automatic Center Punch with Adjustable Stroke ONE-HANDED SPRING IMPACT  automatic center punch has one-handed impact operation, no hammer needed ADJUSTABLE SPRING TENSION - spring tension adjusts for light or heavy strokes, marking, punching and staking MARKS HOLE LOCATIONS  accurate center punch prevents drill bit from traveling, starts drill, nail or screw holes HARDENED STEEL POINT  hardened alloy steel point - 90 day warranty on parts and workmanship STAINLESS STEEL BODY  stainless steel rounded shank body has knurled finger grip